In electronics a NOT gate is more commonly called an inverter. The circle on the symbol is called a bubble, and is used in logic diagrams to indicate a logic negation between the external logic state and the internal logic state (1 to 0 or vice versa).
A weather watch, on the other hand, typically refers to an alert issued to indicate that conditions are favorable for the development of dangerous weather patterns, although the dangerous weather conditions themselves are not currently present.
Think of it this way: A watch means watch out; a warning means take cover. A watch means you need to be aware of the weather, said Dave Nicosia, the warning coordinator for the National Weather Service's Binghamton office. A warning means to take action..